Description of the Related Art
Operating a CD-ROM drive in a computer system has required booting an operating system and loading and utilizing a CD-ROM drive application. The RAM-based CD-ROM device driver of the CD-ROM drive application allowed for operation of the CD-ROM drive. The lengthy duration of the booting process for an operating system and the considerable user interaction required by a CD-ROM drive application render playing an audio CD in the CD-ROM drive of a computer system, as opposed to in a conventional audio CD player, undesirable. An audio CD player, unlike a CD-ROM drive of a computer system, does not involve a timely initialization process and substantial user interaction. As such, despite the CD-ROM drive present in conventional computer systems, users have maintained a separate audio CD player in place of the portable computer. In addition, where a user is away from his or her audio CD player, a conventional computer system due to its initialization and user interaction requirements is unsuited to playing an audio CD as quickly and easily as allowed by a conventional audio CD player. Because of the initialization process and user interaction required, portable computer users would often carry a separate audio CD player for music listening even though the portable computer had music playing capability. Also, since a CD-ROM drive application was dependent upon an operating system, it was necessary to use a display screen to visually indicate to the user when a CD-ROM drive application was being operated. As such, portable computer users have been required to maintain the portable computer case containing a portable computer in its open state to determine the status of a CD-ROM drive application.
Further, a conventional computer system has required a user to access numerous locations, software and hardware, to adjust the volume and other settings of various audio sources such as a CD, wave, and synthesizer for music listening. These locations typically include a mixer in a Windows CD-ROM drive application for controlling the volume of audio sources, a software master volume control in a Windows task bar, and a hardware volume thumbwheel. As these volume control sources controlled volume independent of each other, it was necessary for a user to sort through cumbersome CD-ROM drive software to adjust the volume of the appropriate audio sources. In light of the software nature of certain volume controls, it was also necessary to maintain the portable computer case in its open state with the display screen visible to a user to allow for certain volume adjustments during music listening.